Back in the 1980s, when the Chicago Cubs unveiled the idea of a fan convention during the offseason, about 2,500 people showed up for the inaugural event.

This past November – soon after the Cubs were once again bounced from the playoffs – tickets went on sale for the 24th annual gathering, which takes place this weekend at the Hilton Chicago. Fans rushed to pay $60 apiece, and the more than 10,000 tickets available were sold out – in less than an hour.

Though teams have been slow to adopt them, fan conventions are on the rise in the sports world. More and more pro franchises are putting on the offseason event where players past and present hobnob with fans for a few days at a hotel, exhibition hall or at the home stadium. Most of the teams who host them have not captured a championship in years, if not decades, and need to generate the type of buzz that a title can do on its own.

Of course, fan conventions aren’t unique to sports: aficionados of television shows such as Star Trek and The Andy Griffith Show have united to celebrate their love of the characters and episodes. But stars of those shows eventually pass away, whereas in sports, there’s always a new generation of athletes ready to greet their admirers.

The San Francisco Giants will hold their 16th annual FanFest in February at AT&T Park. Last year, more than 20,000 attended the free event. Fans can explore dugouts, tour clubhouses, walk on the warning track and even be interviewed on KNBR 680, a sponsor of the one-day gathering.

”There’s this atmosphere that it may be rainy and cold outside, but it’s baseball season in here,” said Mario Alioto, Giants senior vice president of corporate marketing, who noted the FanFest occurs just as the team is launching single-game tickets sales. “Well before we’re ready to open, the line is a mile long,”

In Denver, the Broncos held their sixth annual Fan Fair in Invesco Field at Mile High this past June. Tickets for a family of five cost $50 total, or adults could procure a weekend pass for $25. What did fans get for the price? They chatted with coaches, players, cheerleaders and even the team mascot. They got autographs, took photos and purchased memorabilia.

Though teams are almost always the ones creating and implementing fan conventions, three Oakland fans put together the first Raider convention in September. As might be expected among the Silver & Black faithful, the gathering was a raucous affair. According to the Web site, “inside, local band and Bay Area fan favorite, Raiderhead, rocked the house. Outside, there was a DJ, and the Mosley Mayorga fight was broadcast on the big screen.”

How did it all begin? John McDonough, a former Cubs marketing executive who now is president of the Chicago Blackhawks, was not happy that after the Cubs took their last swing during the season, fans heard little about the team again until spring training.

”I didn't understand why sports teams didn’t market themselves 12 months a year,” he said. “I didn’t understand why we just turned it over to the Bears, Bulls and Blackhawks.”

Ironically, since McDonough turned his attention to the once-moribund Blackhawks, they’ve started to steal attention from the Cubs. Last summer, the franchise held its first – and the NHL’s first – fan convention at the Hilton. More than 8,000 Blackhawk backers appeared. Even though both the Cubs and the Chicago White Sox were perched in first place at the time, the Blackhawks’ convention enjoyed top billing in the Chicago Tribune’s sports section.

Aside from energizing rabid fans during the offseason, McDonough points out the revenue benefits of conventions, which usually occur when a team’s schedule is out and after free agents have been signed.

”It impacts merchandise and ticket sales. We improved from 3,500 season-ticket holders (in 2007-2008) to 14,000 this year. The fan convention was right in the epicenter of that,” he said.

Chicago, in fact, seems to be the epicenter of fan conventions. No city boasts as many teams – the Cubs, White Sox, Bears and Blackhawks – who put on fan conventions. And sometimes, it’s not just the players who are the draw.

McDonough remembers trying to persuade broadcaster Harry Caray to serve as honorary chairman of Cubs’ fan conventions. And he convinced the fun-loving legend to attend through an appealing description of the festivities.

”I explained that it would be a giant cocktail party of 5,000-10,000 of your closest friends, he could be the host and it wouldn’t cost him anything,” recalled McDonough, who attributes part of the convention's annual success to Caray’s presence. “He loved it.”